Biochemistry 4th LE 2017 Flashcards
A.B. 18 years old male, developed gum bleeding on routine brushing of his teeth, His diet is lacking in fresh citrus fruits and vegetables. Which vitamin is most likely deficient? A. A B. B1 C. C D. K
C. C
A.B. 18 years old male, developed gum bleeding on routine brushing of his teeth, His diet is lacking in fresh citrus fruits and vegetables.
A.B. is unable to synthesize this vitamin from dietary glucose due to the absence of which of the following enzyme?
A. Gulonase
B. Gulonate decarboxylase
C. Gulonolactone oxidase
D. Gulonic dehydrogenase
C. Gulonolactone oxidase
A.B. 18 years old male, developed gum bleeding on routine brushing of his teeth, His diet is lacking in fresh citrus fruits and vegetables.
The gum bleeding is due to which of the following derangement?
A. Defective synthesis of capillary collagen
B. Deficiency of clotting factors & platelets
C. Increased fibrinolytic activity in mucosal surfaces
D. Increased heparin biosynthesis
A. Defective synthesis of capillary collagen
Raphael, a 2-year old male was given triple anti-TB treatment due to primary pulmonary tuberculosis.
Which of the following vitamins should be part of the therapeutic regimen?
A. Cobalamin
B. Niacin
C. Pyridoxine
D. Riboflavin
C. Pyridoxine
Raphael, a 2-year old male was given triple anti-TB treatment due to primary pulmonary tuberculosis. Pyridoxine is the most important vitamin in the metabolism primarily of which of the following macromolecules? A. Amino acids B. Carbohydrates C. Lipids D. Nucleic Acids
A. Amino acids
Raphael, a 2-year old male was given triple anti-TB treatment due to primary pulmonary tuberculosis.
Deficiency of this vitamin results to decreased synthesis of which of the following neurotransmitters:
B. Catecholamines
C. Nitric Oxide
D. Glutamate
B. Catecholamines
Lola Agnes, 65 years old, keeps on advising her grandchildren to avoid eating well-milled rice.
Which of the following vitamins becomes deficient upon consumption of well-polished rice?
B. Folic acid
C. pantothenic acid
D. Thiamine
D. Thiamine
Lola Agnes, 65 years old, keeps on advising her grandchildren to avoid eating well-milled rice.
A diet deficient in this vitamin will decrease ATP synthesis due to direct inhibition of which of the following reactions?
A. Electron transport along the mitochondrion
B. Catabolism of the branched chained amino acids
C. Oxidative decarboxylation in the Krebs Cycle
D. Substrate level phosphorylations of glycolysis
C. Oxidative decarboxylation in the Krebs Cycle
Lolo Freddie, 60-year-old, underwent total gastrectomy 5 years ago for gastric cancer. Three months later, his wife noted him to be pale…
Absorption of which vitamin will be deficient in Lolo Freddie?
A. Ascorbic acid
B. Cobalamin
C. Folic Acid
D. Pyridoxine
B. Cobalamin
Lolo Freddie, 60-year-old, underwent total gastrectomy 5 years ago for gastric cancer. Three months later, his wife noted him to be pale…
Which of the following intrinsic factor in the prevention of pernicious anemia?
A. Facilitates GIT absorption of vitamin B12
B. Increases GIT absorption of Vitamin B6
C. Stimulates the bone marrow to synthesize RBCs
A. Facilitates GIT absorption of vitamin B12
Lolo Freddie, 60-year-old, underwent total gastrectomy 5 years ago for gastric cancer. Three months later, his wife noted him to be pale…
Which of the following enzyme is decreased in pernicious anemia?
A. Alanine amino transferase
B. Dopamine decarboxylase
C. Glycogen phosphorylase
D. Methyl Malonyl CoA Mutase
D. Methyl Malonyl CoA Mutase
Tita Yolanda, 56-year-old widow, self-medicated on oral antibiotics due to fever of 3 weeks duration. She consulted due to spontaneous hematomas on her right thigh. Lab results showed prolonged coagulation profiles.
Which of the following fat soluble vitamins is decreased with prolonged antibiotic therapy?
A. A
B. Vitamin D
C. E
D. K
D. K
Tita Yolanda, 56-year-old widow, self-medicated on oral antibiotics due to fever of 3 weeks duration. She consulted due to spontaneous hematomas on her right thigh. Lab results showed prolonged coagulation profiles
What is the role of this above vitamin in preventing spontaneous bleeding?
A. Carboxylation of glutamyl residues of clotting factors
B. Enhancement of platelet activation and aggregation
C. Increases conversion of ferric ion to the ferrous state
A. Carboxylation of glutamyl residues of clotting factors
Tita Yolanda, 56-year-old widow, self-medicated on oral antibiotics due to fever of 3 weeks duration. She consulted due to spontaneous hematomas on her right thigh. Lab results showed prolonged coagulation profiles
Dicumerol is an anticoagulant which directly inhibits which of the following enzyme?
A. Quinone reductase
B. Epoxide Reductase
C. Hydroxylase
D. Inhibition of red blood cell membrane hemolysis
B. Epoxide Reductase
A 19 year old Filipina female stayed in Finland for 6 months. Due to cold weather she stayed mostly indoors so she had limited sunlight exposure. On the 5th month she developed carpopedal spasm; serum Calcium was low. The hypocalcemia is due to? A. Hyperparathyroidism B. hyperparathyroidism C. Hypervitaminosis D D. Hypovitaminosis D
D. Hypovitaminosis D
A 19 year old Filipina female stayed in Finland for 6 months. Due to cold weather she stayed mostly indoors so she had limited sunlight exposure. On the 5th month she developed carpopedal spasm; serum Calcium was low.
Which of the following is true of Vitamin D synthesis?
A. Cholecalciferol undergoes hydroxylation initially in the kidneys and then the liver
B. liver hydroxylation is the major control point in the biosynthetic pathway
D. Preformed vit D in the skin is photolyzed by UV sunlight into Previtamin D3
D. Preformed vit D in the skin is photolyzed by UV sunlight into Previtamin D3
35 years old female, was started on methotrexate due to choriocarcinoma.
This drug inhibits DNA synthesis of cancer cells by inhibiting this enzyme.
A. Dihydrofolate reductase
B. Formyl transferase
C. Serine hydroxymethyl transferase
D. Thymidylate synthase
A. Dihydrofolate reductase
Inhibition of this enzyme results to which of the following desirable effects?
A. Decreased FH4 pool for DNA synthesis for CA cells
B. Decreased N5-mathyl FH4 for synthesis of SAM
D. Increased ribonucleotide biosynthesis
A. Decreased FH4 pool for DNA synthesis for CA cells
This substituted folate is involved in the synthesis of s-adenosylmethionine: A. N5-methyl FH4 B. N-formyl FH4 C. N5, N10 methenyl FH D. N5, N10-methylene FH4
A. N5-methyl FH4
Which of the following metabolic reactions would be inhibited by consumption of large amounts of raw egg white? A. Carboxylation B. Decarboxylation C. Dehydrogenation D. Methylation
A. Carboxylation
The following vitamin does not possess an antioxidant property: A. Ascorbic acid B. Carotene C. Tocopherol D. Menadione
D. Menadione
Vitamins perform metabolic roles in man in the form of: A. Apoenzymes B. Coenzyme C. Isoenzymes D. Zymogens
B. Coenzyme
What is the ratio of CO2/O2 in the oxidation of fats? A. 0.7 B. 0.8 C. 0.9 D. 1.0
A. 0.7
Which of the ff. essential amino acids does peanut lack? A. Leucine B. Lysine C. Methionine D. Phenylalanine
B. Lysine
How many servings of vegetables should be included in the daily diet in order to attain optimal growth? A. 2-4 B. 3-5 C. 9-11 D. Unlimited
B. 3-5
How many calories of CHO per 100kcal of TCR should be included in the diet in order to prevent Ketoacidosis? A. 2 B. 3 C. 4 D. 5
D. 5
Which is true about HCO3 transport in the GIT?
B. A major mechanism for HCO3 secretion is via Cl-HCO3 exchangers
C. Down regulation in Adenoma transports 2 HCO3- in exchange for 1 Cl- ion.
D. Putative Anion Transporter transports 1 HCO3- in exchange for 2 Cl- ions
B. A major mechanism for HCO3 secretion is via Cl-HCO3 exchangers
Which is the function of the tight junction (T.J.) in the generation of barrier function of the GIT?
A. Claudins determines the permeability of tight junctions
B. Development of E-cadherens bonds determines permeability
C. JAMs determine size and ionic permeability of the T.J. pores.
D. Occludens determine charges of ions that enter the T.J.
A. Claudins determines the permeability of tight junctions
What controls the opening or the closing of the T.J.?
B. ↓ JAMs stimulate opening of tght junction
C. ↑ Cadherins increases opening of the T.J.
D. Zonula occludens link to I.C. cytoskeleton
D. Zonula occludens link to I.C. cytoskeleton
What is the response of the T.J. to Na+ nutrient absorption after a full meal?
B. Fluid absorption in the small intestine
C. Fluid absorption in the distal colon
D. HCO3 secretion in the TJ
B. Fluid absorption in the small intestine
Which is a characteristic of the polarized phenotype of enterocytes?
A. Apical pole: NCO3
B. Apical pole: NHE3
C. Basolateral pole: receptors of bacteria
D. Basolateral pole: H+-K+-ATPase
B. Apical pole: NHE3
Which of the following transporters explains why secretion is predominant in the crypts of the GIT?
A. CFTR
C. NKCC1
D. NHE3
A. CFTR
What is the effect of increased activity of SGLT 1 after a meal on Cl transport?
A. ↑ absorption paracellularly
C. ↓ secretion paracellularly
D. ↓ secretion transcellularly
A. ↑ absorption paracellularly
Which mechanism is involved in the formation of solid stools in the distal colon?
A. ↓ chloride secretion
C. ↑ NaCl absorption
D. ↑ ENaC activity
D. ↑ ENaC activity